1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25 #include "main/glheader.h"
26 #include "main/macros.h"
27 #include "main/samplerobj.h"
28 #include "main/teximage.h"
29 #include "program/prog_instruction.h"
30
31 #include "s_context.h"
32 #include "s_fragprog.h"
33 #include "s_span.h"
34
35 /**
36 * \brief Should swrast use a fragment program?
37 *
38 * \return true if the current fragment program exists and is not the fixed
39 * function fragment program
40 */
41 GLboolean
_swrast_use_fragment_program(struct gl_context * ctx)42 _swrast_use_fragment_program(struct gl_context *ctx)
43 {
44 struct gl_program *fp = ctx->FragmentProgram._Current;
45 return fp && !(fp == ctx->FragmentProgram._TexEnvProgram
46 && fp->arb.NumInstructions == 0);
47 }
48
49 /**
50 * Apply texture object's swizzle (X/Y/Z/W/0/1) to incoming 'texel'
51 * and return results in 'colorOut'.
52 */
53 static inline void
swizzle_texel(const GLfloat texel[4],GLfloat colorOut[4],GLuint swizzle)54 swizzle_texel(const GLfloat texel[4], GLfloat colorOut[4], GLuint swizzle)
55 {
56 if (swizzle == SWIZZLE_NOOP) {
57 COPY_4V(colorOut, texel);
58 }
59 else {
60 GLfloat vector[6];
61 vector[SWIZZLE_X] = texel[0];
62 vector[SWIZZLE_Y] = texel[1];
63 vector[SWIZZLE_Z] = texel[2];
64 vector[SWIZZLE_W] = texel[3];
65 vector[SWIZZLE_ZERO] = 0.0F;
66 vector[SWIZZLE_ONE] = 1.0F;
67 colorOut[0] = vector[GET_SWZ(swizzle, 0)];
68 colorOut[1] = vector[GET_SWZ(swizzle, 1)];
69 colorOut[2] = vector[GET_SWZ(swizzle, 2)];
70 colorOut[3] = vector[GET_SWZ(swizzle, 3)];
71 }
72 }
73
74
75 /**
76 * Fetch a texel with given lod.
77 * Called via machine->FetchTexelLod()
78 */
79 static void
fetch_texel_lod(struct gl_context * ctx,const GLfloat texcoord[4],GLfloat lambda,GLuint unit,GLfloat color[4])80 fetch_texel_lod( struct gl_context *ctx, const GLfloat texcoord[4], GLfloat lambda,
81 GLuint unit, GLfloat color[4] )
82 {
83 const struct gl_texture_object *texObj = ctx->Texture.Unit[unit]._Current;
84
85 if (texObj) {
86 SWcontext *swrast = SWRAST_CONTEXT(ctx);
87 GLfloat rgba[4];
88 const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, unit);
89
90 lambda = CLAMP(lambda, samp->Attrib.MinLod, samp->Attrib.MaxLod);
91
92 swrast->TextureSample[unit](ctx, samp, ctx->Texture.Unit[unit]._Current,
93 1, (const GLfloat (*)[4]) texcoord,
94 &lambda, &rgba);
95 swizzle_texel(rgba, color, texObj->Attrib._Swizzle);
96 }
97 else {
98 ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
99 }
100 }
101
102
103 /**
104 * Fetch a texel with the given partial derivatives to compute a level
105 * of detail in the mipmap.
106 * Called via machine->FetchTexelDeriv()
107 * \param lodBias the lod bias which may be specified by a TXB instruction,
108 * otherwise zero.
109 */
110 static void
fetch_texel_deriv(struct gl_context * ctx,const GLfloat texcoord[4],const GLfloat texdx[4],const GLfloat texdy[4],GLfloat lodBias,GLuint unit,GLfloat color[4])111 fetch_texel_deriv( struct gl_context *ctx, const GLfloat texcoord[4],
112 const GLfloat texdx[4], const GLfloat texdy[4],
113 GLfloat lodBias, GLuint unit, GLfloat color[4] )
114 {
115 SWcontext *swrast = SWRAST_CONTEXT(ctx);
116 const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
117 const struct gl_texture_object *texObj = texUnit->_Current;
118
119 if (texObj) {
120 const struct gl_texture_image *texImg = _mesa_base_tex_image(texObj);
121 const struct swrast_texture_image *swImg =
122 swrast_texture_image_const(texImg);
123 const struct gl_sampler_object *samp = _mesa_get_samplerobj(ctx, unit);
124 const GLfloat texW = (GLfloat) swImg->WidthScale;
125 const GLfloat texH = (GLfloat) swImg->HeightScale;
126 GLfloat lambda;
127 GLfloat rgba[4];
128
129 lambda = _swrast_compute_lambda(texdx[0], texdy[0], /* ds/dx, ds/dy */
130 texdx[1], texdy[1], /* dt/dx, dt/dy */
131 texdx[3], texdy[3], /* dq/dx, dq/dy */
132 texW, texH,
133 texcoord[0], texcoord[1], texcoord[3],
134 1.0F / texcoord[3]);
135
136 lambda += lodBias + texUnit->LodBias + samp->Attrib.LodBias;
137
138 lambda = CLAMP(lambda, samp->Attrib.MinLod, samp->Attrib.MaxLod);
139
140 swrast->TextureSample[unit](ctx, samp, ctx->Texture.Unit[unit]._Current,
141 1, (const GLfloat (*)[4]) texcoord,
142 &lambda, &rgba);
143 swizzle_texel(rgba, color, texObj->Attrib._Swizzle);
144 }
145 else {
146 ASSIGN_4V(color, 0.0F, 0.0F, 0.0F, 1.0F);
147 }
148 }
149
150
151 /**
152 * Initialize the virtual fragment program machine state prior to running
153 * fragment program on a fragment. This involves initializing the input
154 * registers, condition codes, etc.
155 * \param machine the virtual machine state to init
156 * \param program the fragment program we're about to run
157 * \param span the span of pixels we'll operate on
158 * \param col which element (column) of the span we'll operate on
159 */
160 static void
init_machine(struct gl_context * ctx,struct gl_program_machine * machine,const struct gl_program * program,const SWspan * span,GLuint col)161 init_machine(struct gl_context *ctx, struct gl_program_machine *machine,
162 const struct gl_program *program, const SWspan *span, GLuint col)
163 {
164 GLfloat *wpos = span->array->attribs[VARYING_SLOT_POS][col];
165
166 /* ARB_fragment_coord_conventions */
167 if (program->info.fs.origin_upper_left)
168 wpos[1] = ctx->DrawBuffer->Height - 1 - wpos[1];
169 if (!program->info.fs.pixel_center_integer) {
170 wpos[0] += 0.5F;
171 wpos[1] += 0.5F;
172 }
173
174 /* Setup pointer to input attributes */
175 machine->Attribs = span->array->attribs;
176
177 machine->DerivX = (GLfloat (*)[4]) span->attrStepX;
178 machine->DerivY = (GLfloat (*)[4]) span->attrStepY;
179 machine->NumDeriv = VARYING_SLOT_MAX;
180
181 machine->Samplers = program->SamplerUnits;
182
183 /* if running a GLSL program (not ARB_fragment_program) */
184 if (ctx->_Shader->CurrentProgram[MESA_SHADER_FRAGMENT]) {
185 /* Store front/back facing value */
186 machine->Attribs[VARYING_SLOT_FACE][col][0] = 1.0F - span->facing;
187 }
188
189 machine->CurElement = col;
190
191 /* init call stack */
192 machine->StackDepth = 0;
193
194 machine->FetchTexelLod = fetch_texel_lod;
195 machine->FetchTexelDeriv = fetch_texel_deriv;
196 }
197
198
199 /**
200 * Run fragment program on the pixels in span from 'start' to 'end' - 1.
201 */
202 static void
run_program(struct gl_context * ctx,SWspan * span,GLuint start,GLuint end)203 run_program(struct gl_context *ctx, SWspan *span, GLuint start, GLuint end)
204 {
205 SWcontext *swrast = SWRAST_CONTEXT(ctx);
206 const struct gl_program *program = ctx->FragmentProgram._Current;
207 const GLbitfield64 outputsWritten = program->info.outputs_written;
208 struct gl_program_machine *machine = &swrast->FragProgMachine;
209 GLuint i;
210
211 for (i = start; i < end; i++) {
212 if (span->array->mask[i]) {
213 init_machine(ctx, machine, program, span, i);
214
215 if (_mesa_execute_program(ctx, program, machine)) {
216
217 /* Store result color */
218 if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
219 COPY_4V(span->array->attribs[VARYING_SLOT_COL0][i],
220 machine->Outputs[FRAG_RESULT_COLOR]);
221 }
222 else {
223 /* Multiple drawbuffers / render targets
224 * Note that colors beyond 0 and 1 will overwrite other
225 * attributes, such as FOGC, TEX0, TEX1, etc. That's OK.
226 */
227 GLuint buf;
228 for (buf = 0; buf < ctx->DrawBuffer->_NumColorDrawBuffers; buf++) {
229 if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DATA0 + buf)) {
230 COPY_4V(span->array->attribs[VARYING_SLOT_COL0 + buf][i],
231 machine->Outputs[FRAG_RESULT_DATA0 + buf]);
232 }
233 }
234 }
235
236 /* Store result depth/z */
237 if (outputsWritten & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
238 const GLfloat depth = machine->Outputs[FRAG_RESULT_DEPTH][2];
239 if (depth <= 0.0F)
240 span->array->z[i] = 0;
241 else if (depth >= 1.0F)
242 span->array->z[i] = ctx->DrawBuffer->_DepthMax;
243 else
244 span->array->z[i] =
245 (GLuint) (depth * ctx->DrawBuffer->_DepthMaxF + 0.5F);
246 }
247 }
248 else {
249 /* killed fragment */
250 span->array->mask[i] = GL_FALSE;
251 span->writeAll = GL_FALSE;
252 }
253 }
254 }
255 }
256
257
258 /**
259 * Execute the current fragment program for all the fragments
260 * in the given span.
261 */
262 void
_swrast_exec_fragment_program(struct gl_context * ctx,SWspan * span)263 _swrast_exec_fragment_program( struct gl_context *ctx, SWspan *span )
264 {
265 const struct gl_program *program = ctx->FragmentProgram._Current;
266
267 /* incoming colors should be floats */
268 if (program->info.inputs_read & VARYING_BIT_COL0) {
269 assert(span->array->ChanType == GL_FLOAT);
270 }
271
272 run_program(ctx, span, 0, span->end);
273
274 if (program->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_COLOR)) {
275 span->interpMask &= ~SPAN_RGBA;
276 span->arrayMask |= SPAN_RGBA;
277 }
278
279 if (program->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
280 span->interpMask &= ~SPAN_Z;
281 span->arrayMask |= SPAN_Z;
282 }
283 }
284
285